The need for separating liquid from a liquid-laden solid material may arise in a variety of applications. As crude oil is refined, for example, a residual material known as petroleum coke may be generated. Petroleum coke is a granular solid that is highly combustible. It is typically created in a coking drum having removable end caps, wherein a single piece of petroleum coke remains lodged inside the drum. To remove the petroleum coke from the drum, the end caps are removed and a hydraulic drill is inserted through a center of the piece of petroleum coke. The hydraulic drill first passes axially through the drum to create a two to three foot bore through the center of the petroleum coke. The drill is then pivoted so that its head is aligned radially with respect to the drum axis, and the drill is rotated to cut through and dislodge the petroleum coke material located nearer the drum. During the drilling and cutting processes, water is typically used to assist removal of the coke from the drum. Eventually, all of the petroleum coke and water will drop out of the bottom of the drum.
Further processing of the petroleum coke and water has typically included passing the material through a screen into a pit. The water and the petroleum coke is then pulled out of the pit and discharged into an evaporation field. Once the water content is sufficiently reduced, the petroleum coke is then loaded into rail cars which ultimately discharge the coke onto a conveyor. Consequently, the petroleum coke must be handled at separate transfer points, such as from the pit to the evaporation field and from the evaporation field to the conveyor. Furthermore, such handling often requires the use of rail cars which are overly expensive and time consuming to use. Still further, the use of evaporating pits requires a substantial amount of time for the water content of the petroleum coke to drop to a level sufficient for further handling, transport, and/or use.
Some petroleum coke dewatering processes are known which attempt to use screens to retain the solid material while allowing the liquid to pass through. Such systems may employ conventional or vibrating screens. A common problem with such screens, whether conventional or vibrating, is that solids suspended in the liquid tend to clog the screen, thereby interrupting the dewatering process.